A Pulpy-Verse (some ideas stolen from GURPS "tales of the space patrol")
This is a world of High Adventure, where pulp adventure localities are as normal as New Jersey and often safer to visit. Currently the quarreling terrestrial governments are shakily united as allies against the menacing power of the Overlord of Jupiter, against which the earth governments fought a short but brutal war 2001-2003.
The world is dominated by the Five Great Powers: the USA, greatest of all, and its dependencies and economic partners in Latin America, Japan, and the Philippines; China, a capitalist dictatorship under the rule of the Insidious Doctor's great-great-grandson (with his ancient grandmother occasionally doing a bit of back-seat driving); the USSR, which nowadays has an informal alliance with the US against the common Yellow Menace: the Third Reich, which glares at the USSR across the "dead zone" left by the ultra-catalyst by which the Soviets ended the Six Years War, and breed like rabbits by government degree; (in this timeline's WWII, the US stayed out of Europe and other events went rather differently: Hitler was assassinated by one of his generals in 1943) and, although not as strong as it once was, the still powerful, rich, and deeply cosmopolitan British Empire. (Oh, and then there's the Lost Kingdom of ancient Egypt, with their anti-gravity metal flying boats and sun-powered weapons. And we shouldn't forget Shamballah or the Deep Ones).
United States of America - dominates the Americas through a series of economic agreements rather more extensive than NAFTA OTL (although Canada trades more with the Empire and less with the US), and has powerful influence in the west Pacific through its protectorate over the Philippines which has a relation to the US similar to Puerto Rico in our world (Puerto Rico is here the 51st state, and there are a _lot_ of Filipinos in the USA), and Japan, which was far more thoroughly "de-fascist-ized" after the Pacific War. It is the most technologically advanced of nations, with the worlds' most advanced space program, (the Long Island spaceport is the world's largest, and a common tourist destination) the biggest and shiniest cities, and more be-goggled, lab-coating wearing super-scientists than anyone else.
It's a bit more sexist and sexually conservative US than ours – skirts and old-fashioned modes of dress are more common among women, and the Pill was later in arriving – but it's also a somewhat less racist society. (Fewer poor blacks and plenty of wealthy dusky-skinned visitors from the British Empire and more occasionally from the French Union have also undermined racist stereotypes). In a world of Super-Science, religious fundamentalists are rather cut off from the political system, which is breeding up trouble for the future as they increasingly try to seal themselves off from "decadent" society. Blue-collar jobs are abundant, globalization and the shipping of jobs abroad not having gone very far in this world.
There is less in the way of suburbs: cities are cleaner and with far less crime than OTL, and most impressive-looking: New York, Chicago, and San Francisco have positively alarming Frank-Paulesque skylines in this TL, with a number of the new buildings designed with Martian super-plastics looking impossibly top-heavy to natives of our world. Wildly swooping roads criss-cross the cities, busy with ultra-fast two-wheel cars balanced by gyroscopes. Cars, clothes, and machinery are garishly colorful, technology is viewed with enthusiasm rather than alarm, and the country's garages are full of young would-be mad scientists trying to develop the new super-invention. The skies at night glow faintly with the spill-off from broadcast power, but that doesn't matter much, since all the more advanced astronomical observatories have moved into space.
President Arthur Savage wishes his old man was around, but given that he was last seen ten years ago leading an expedition into a largely unknown area of Martian desert, and he was ninety-six at the time, he doesn't hope for any help from that quarter. Will the peace with Jupiter be maintained, or does mankind face a new war which it will probably lose?
China remains a harsh dictatorship, as brutally as run as OTL Red China, if with more fiendish intelligence and with a touch more class. It's also a lot richer: it's been modernizing fast since the early 40's, and is, correcting for the effects of our world's rather different technology, where our China is often predicted to be by the late 2030's. It's still not as rich or influential as the US, but its number two with a bullet, and it's gaining at a good clip. It's a lot _cleaner_ than OTL: people have been forcibly moved from coal to electric heat and cooking, Tesla-space powers all industries, and only military vehicles are non-electric. (There is also a lot less spitting than OTL. The Emperor's Reverend Grandmother was a very elegant lady in her day, and the public cleanliness rules are more stringent than OTL Singapore). There is an odd mix of the modern and antique: a fierce pursuit of science and technology, but learning the Confucian Classics is as important to an educated man or woman as Latin and Greek would be to an Oxford man class of 1890, and traditional dress is as strongly encouraged as blue overalls were in Mao's China (although the pigtail, a symbol of submission to Manchu rule, is Right Out). Shanghai is perhaps the world's most decadent city, where human beings, strange drugs from inner Asia, and the hideous products of forbidden science are all for sale- at the right price.
The USSR is a near- (or "guided") democracy: after the Third Period of Correction, the Techno-Socialist Party dominates with the aid of giant robot brains rather than commissars: creating another political party is theoretically possible, but the rules for creating a new party are so stringent that the "opposition" consists of groups that in other countries would be factions within the larger party. Parties based in particularist nationalism are _very_ illegal, although without an Eastern European empire, the USSR has less to worry about in this respect. The USSR claims to be the world's only truly 'rational' and 'scientific' nation, and invests a massive amount of its budget in basic research. The master computer-wranglers have, among other things, made the black market semi-legal, and have encouraged the replacement of collective farms with for-profit farmer-owned collectives, although the government still holds the Commanding Heights of the economy.
The USSR has a much more developed internal communications system than ours did: the country is full of highways, railways, and buzzing little cars which can be repaired almost indefinitely with a rag, a wrench, and perhaps a bit of wire. There are more Soviets than OTL: although growth has been only a bit over replacement for a while, even in the Islamic areas, there's been nothing like our Russia's demographic collapse. And they're enthusiastic about attracting (and converting) immigrants. "Constant reinvention" is the creed of the regime today, and it certainly can be exciting, especially for those evicted from their crumbly but cozy apartments as a new round of Urban Innovation and Renewal gets under way, or the development of a new Truth Drug leads to a new round of Ideological Commitment Tests. (Not that they shoot you for failing anymore, but ending up repairing transistors in Magadan is no picnic either).
Nazi Germany is, well, Nazi Germany: Hitler's assassination was kind of a spur-of-the-moment thing, and the Army failed to remove the Party, although they managed to force a degree of independence from "civilian" control they have never let go. They may have mellowed a bit on race matters – to the point where the long-term objective is the Germanification of 80% of the Slavs still under their control – but Jews, blacks, East Asians, and non-Aryan Indians are still forbidden to become citizens. OTOH, "Aryans" from wherever, (as long as they don't show signs of "mongrelization"), the lighter sorts of Italians, Spaniards, etc., and even Arabs and Latin Americans of an appropriate hue are welcomed – in spite of vigorously pro-reproduction policies (only lately have non-party female "race traitors" escaped from the risk of being dragged off to a "fertility clinic" by the Eugenics Police), there are still fewer Reich citizens than Soviets or Americans – let alone Chinese! Berlin is quite a tourist spot. 
The country is still a dictatorship, although now more of a corporate phenomenon than a one-man show – there are limits how far Fuhrer Heisenberg can go in challenging the power of the Army, the Secret Police (the old SS was broken up after Hitler's death), and the Party – which has over 70 years professionalized itself to the point where it is actually a well-disciplined political party rather than a club for thugs and street-fighters favored by Hitler. It is also capitalist, depressingly commercial-minded from the point of view of the few surviving old radicals, and has spent more per capita on space exploration and colonization than any other country – there, on Venus and the Asteroids and beyond, is true Lebenstraum, the room for a Germany of billions. Germany is also very big on Post-Humanism, and crude cybernetics and body-enhancing drugs are common. Ideologically and genetically pure Aryans are raised free of corrupting influence in moon-castles, to serve as seed stock for extraterrestrial settlements. The Reich has close ties to the Argentine dictatorship, and supports its efforts to puppetize Brazil, where Germany already has a great deal of influence.
The British Empire is still an Empire, although it is increasingly just called "The Empire." The entry of India into self-government as five separate Dominions (plus Tribal Areas, Noble Protectorates, and the Free City of Bombay) helped calm fears the Empire would eventually become "India and its li'l buddies", and the number of Dominions is now 14, although much of Africa has not yet become fully self-governing: it is generally agreed that an educated and commercial class of a certain size is needed to allow for self-government (the Tanzanians have been rather loudly disagreeing of late, noting that such interpretations were taken a lot more loosely 46 years ago, when still piss-poor Tamil S. India became a full Dominion). The Empire's administrative center was moved in 1981 from the UK to more neutral – and close to the statistical center of its population – Sri Lanka.
South Africa is the Empire's Problem Child: having broken with the rest of the Empire over its racial policies, it had its first free elections in 1990 and returned to the Imperial fold in 1992. In spite of massive investment, it remains only slightly wealthier than Nigeria, and the most crime-ridden state in the Empire: a legacy of the disastrous policies of Apartheid. Palestine is doing OK, since the Jews have settled deep under the Atlantic instead . Egypt is one of the empire's chief workshops; Islamic Universalist Terrorism is an increasing problem, but the British are being helped by the Secret Cultists who still follow the Ancient Gods of Egypt (since regular cooperation became the norm, mummy attacks are down by 90%).
The Indian states occasionally talk a bit about unification, but unwillingness to agree as to cultural autonomy, strength of the central government, and who gets the capital (it was offered to Bombay, but they politely turned it down) had led to some impressive meltdowns at Imperial Policy conferences. The UK has outsourced most of its heavy industry to other parts of the Empire, but remains a leader in high-tech. Currently, Kukuanaland has been much in the news: extraordinarily rich in gold and diamonds, this British protectorate's traditional-minded monarchy is now suffering from Red Rebellion and Imperial troops are being rushed to the area.
Lesser states include decadent Italy under Mussolini III, which has withdrawn from Empire and taken a largely neutral role in international affairs: the Syndicalist French Empire and their Spanish and Vietnamese client states, busily at work trying to green the Sahara with atomic power and imported Martian vegetation; the Technocratic Scandinavian Community; the Argentine Junta, with its mad plans to unite all of Latin America under its rule; and the rich but nervous Benelux Union, which hangs close with the US and the British in the face of alarming neighbors. Haiti, a crapsack nation in our world, has managed to make lemonade from the sour lemons of Voodoo, and through mind control and zombie labor has managed to maintain control of all of Hispaniola and hold at bay most gunboat diplomacy. Transylvania is known for its rich variety of cultures and peoples, its traditional tolerance, and its horrors of the night, while Dacia-Macedonia-Transbalkania is widely reputed as a place where anything can happen, and probably will.
The there is the regime of the Mad Mullah, whose fanatical warriors work toward the final unification of all Islam: his agents are active in every Islamic nation, and work to undermine the British and French Empires (the Chinese have their own Muslims, but an alliance of convenience exist there: the Mullah also has cordial relations with the Reich). The Islamic Union has made big strides in modernization, but is currently banned from having its own spaceships by the major powers, which worry about the destructive potential of Islamic hashishim at the controls of a spaceship.
LOST CITIES, HIDDEN CIVILIZATION, AND SECRET POWERS
All the mysterious lost kingdoms of old have by now been found: the impenetrable thorn forest burned down, the impassable desert crossed by rail and airplane, the Veil of Illusion penetrated by satellite photography. Surviving Carthaginians now learn about their ancestors the Gauls, the Great White Apes spend far more time than they would like learning sign language and are getting sick of Jane Goodall, and Shangri-La has gone badly downhill since the tourists started arriving. On the other hand the pale, mushroom-growing Troglodytes have been able to maintain some autonomy within the French Union by being able to collapse entry tunnels when the French get too pushy, and have managed to develop a profitable trade in mushroom-derived products: while the Hidden Egyptian Civilization has managed to maintain independence from the British Empire through its Ancient Secret Science (which other nations are distinctly annoyed at their not sharing) and its influence over Secret Cults in north Africa.
Some Lost Cities turned out to be, well, rather unpleasant places, and have required the extensive use of atomic energy plus some vigorous government cover-ups. Even more troublesome are the Deep Ones, the strange fish-men of the Pacific Ocean abyss, possibly the descendants of the peoples of sunken Mu. Worshippers of strange and monstrous gods, controlling hordes of deep-sea monsters, they have fortunately so far shown very little interest in the "upper world", but remain a worry for inhabitants of wee little Pacific islands (Hawaii is less popular as a place of residence than in our world).
Shamballah has no official diplomatic relations with the upper world (although its psychic monks do have an annoying habit of communicating by dream with upper-world officials), but it is enough of a power to discourage Chinese occupation of Tibet, and played an important intelligence role in the war with Jupiter. And then there is the mad scientist population, and you never know when one of them is going to emerge from their lair with an army of giant mutant gerbils.
Although the Jovian Menace provides something of a unifying force in terrestrial politics, the Big Powers still don't get along very well. The Russians and the Germans hate each other, the French hate them both, the Chinese aren't very hot on the British, the Americans think they're all second-rate compared to the Glorious Ark of Liberty. The British are good at diplomacy, having been forced over the last century to move from force to persuasion as a way of keeping the Empire together, and often play the part of negotiators and peacemakers. The anti-Jovian alliances and treaties have not brought into the light the various "black book" technological projects pursued by national governments – German Dealings With the Unspeakable and grotesque cybernetics experiments, Soviet experiments with psychic sciences, Chinese efforts to breed armies of giant mutant insects and achieve mind-control through the medium of TV, US experiments with Venusian plagues and the project to use a modified Tesla-Space generator to create a temporary "electron singularity" that would require an H-bomb the size of a building to duplicate in destructive power. A lot of people are now calling for a World Government to deal with the alien menace: the US is positive, as long as it is structured like the US government: the Brits suggest a loosely federal structure like their Empire, perhaps with some sort of unelected figurehead, like a queen or something; the Soviets are more tentative, and want a more "scientifically" organized government with education tests for its members. The Chinese and Germans want nothing to do with it.
PULP BIOLOGY AND GEOLOGY
Vast underground cave systems snake through the depths of the Earth, which heats up rather more slowly than OTL as you go downwards, providing living space for troglodytes, giant mammoth-herders, ape-men, Shamballians, mad scientists, secret Nazi bases, the mysterious and elusive Mole-men, and a large colony of by now rather pallid Jews. Strange beasts from the ancient past are common enough, and dinosaurs are found not only under the Atlantic seafloor but also in South America, the Congo, and Skull Island. (Where an international breeding program is underway to attempt to preserve the endangered Gorilla Giganticus Kong from extinction). Other, stranger beasts are found in the deep seas, from the Colossal Octopus to the Great Sea Serpent to the Shoggoths (Greater and Blue-Spotted).
SCIENCE AND TECHNOLOGY
This world has seen technological developments only made possible by a rather different set of physical laws. In this world, transistorized circuits, due to a different sort of quantum mechanics, simply don't work: computer still run either on tubes or on "circuit boards" of metal-etched glass, although US and British (which is to say, a few Brits, a few Canadians, and a bunch of Indians) researchers are working on building computers that work purely on the principle of interfering light-rays. There is no internet: there are online repositories with enormous depths of well-cataloged knowledge, but it is usually a giant national computer the size of a skyscraper (in the US and British versions, there is a subsection of a few tens of thousands of cubic feet where interested private researchers can contribute their own knowledge, but most people don't consider the ".pub" directory very seriously).
On the positive side, there is T-space: derived from experiments of Tesla, it led in the 1950's to an unlimited power source, for industry, space-drives, and the Electron-Ray. There are no more fossil-fuel power plants, and the only reason there are still gas-burning cars in some countries (mostly in the US) is that with so little demand outside the plastics and synthetics industry, petroleum remains dirt cheap. (As yet, power plants are too unwieldy to use in anything smaller than a _big_ tank, although if you just want a jet of super-high energy electrons, you can build something the size of a rifle – the principal weapon of Our Men and Women in Space.) The T-space powered, electron-cannon armed, electron-jet propelled rocket is the principal military weapon. Heavy tanks are obsolete, since no armor of practical thickness can protect from a high-power electron beam. Given early and easy rocket-ship travel, the development of guided missiles has lagged compared to OTL.
The air is cleaner, and in Europe (which prefers electrical cars and trains anyway) the German woods are untainted by acid rain. Cheap energy has helped many in the third world, who can build their own power plants (a T-space generator, now that the technology has matured, is considerably easier to build, and less dangerous to run, than an atomic power plant) and free themselves from dependence on imported fuel to light their cities and power their (often limited) industries. (Not that there are as many third-world poor as OTL. India is richer, China a lot richer than OTL: and much of Africa is still under colonial and semi-colonial rule). On the other hand, the oil rich countries are a lot poorer: such places as Oman and Bahrain are still sleepy dependencies of the Empire, with a modest income from the plastics industry (the US is running short on oil to satisfy its motorists, but prefers to import from closely tied countries such as Mexico and Venezuela). The Saudis never seized the brass ring, and the Hashemite Dynasty runs Arabia: it is a conservative, pious country with veiled women, but on the other hand the locals aren't flying rocket ships into skyscrapers.
Chemistry is more advanced, as is medicine: some remarkable new drugs have emerged from the seething jungles of Venus, and combined with Chinese breakthroughs in organ transplants and grafting (those political prisoners are good for other things than building railways to outer Sianking), has raised the average lifespan in the richer countries to over 90. Remarkable new synthetics have allowed for wild new Technicolor skyscrapers of unusual shape and swooping sky-bridges, which gives the skyline of big cities in the US and the British Empire a Frank Paul look (the Germans prefer a neo-classical look, the Chinese a faux-Xanadu look with lots of pagodas and winged roofs, while the Soviets like things shiny, metallic and geometric – more "scientific" looking).
TV is now 3-d, not to mention high-definition and Very Large. Movie theatres are few, and tend to specialize in stuff too violent, too spicy, or outré for the TV companies (of which there are fewer than OTL. Cable has been slow to be adopted). No flying cars, alas: computers and power plants remain too bulky to build a genuinely "safe for those at ground level" flyer, and although there are a few cities which are fairly lax about helicopters, getting a license is still almost as hard as OTL.
People travel by rocket, of course, for long distances: this does have the disadvantage that the airports (due to the noise and the need for deep pits to avoid frying the landscape with electron beams) tend to be well outside city limits, which means that you'll always spend much more time going to and fro the airport than on the actual rocket. (Longer still if you are visiting countries with stiff customs regulations, such as Germany, China, or France).
Robots are no more common than OTL: you just can't build an AI inside a human-sized skull with vacuum tubes, no matter how miniaturized. The Soviets have built a computer the size of a city block, which is sentient enough to be deeply neurotic and deeply depressed (Soviet scientists have often come away with splitting headaches after an extended discussion with Marvinski). Computers are much used in business and industry, but it's usually a big ol' computer with lots of peripherals rather than stand-alone units.
Sports remain as popular, lawyers as distrusted, and fast food as ubiquitous and unhealthy as OTL. Governments are more trusted, there is more confidence in progress, and Mans Future in Space looks very bright. On the gripping hand, there is also the unfortunate fact that something like half the world's population lives under dictatorships of one sort or another, although the Soviets have mellowed lately.
THE SOLAR SYSTEM
The moon is as desolate as in our world, aside from radiation-eating, slow-growing "moon coral" (also found on many asteroids), but there are a number of colonies, scientific bases, mines, etc., and grizzled moon-prospectors comb the barren wastes in hopes of a rich strike. The Asteroid Belt is heavily colonized by the major powers (with variable intensity: not too many from the resource-rich British empire, lots of Germans), and is a political hodge-podge, with innumerable little self-proclaimed governments squatting on one asteroid or another, (with heavy electron-beam asteroid mining tools and ships engines convertible to weapons, it is often more trouble than it is worth to kick them off) and the territories of various nations are scattered far and wide, with some of the larger asteroids split between several nations, and small ones owned by corporations.
Venus is only slowly being settled by terrestrials. The swamps and jungles are nasty places even for the best-prepared explorer, and without careful scouting your ship is likely to sink into a swamp, get tangled in the branches of a Kraken-Tree, or, if you're _really_ unlucky, end up right in the crawl path of an Immeasurable Worm. Mercury, OTOH, is hot, airless, and uninhabited save for a small penal colony mining the riches of the Williamson Caverns (which are deep within the planet, and have a stable temperature of a mere 110 Farehnheit.)
Mars is inhabited by the Red Men (descended from proto - homo sapiens imported by the ruling Mind Masters to serve as more skillful "mounts" than the local hexapodal apes and the semi-sapient four-armed "green men" a hundred thousand years ago). Tough and warlike and with an advanced science, they are no real threat to earth, too concerned with their ancient and ongoing conflict with their former masters and defending their desert cities to get involved with wars off-planet. (In any event, although human in ancestry, the Red Men take months to adapt to Earth's gravity). The Warlord of Mars is sympathetic to Earthmen, but fails to see any profit in risking the wrath of the Jovians.
And then there is Jupiter, whose icy Cold Folk objected most strenuously to Terrestrial efforts to exploit Io; Io, the fiery moon, never settled by the Jovians, but claimed as theirs by gravitational domain. Although the end of the conflict left the Earth Alliance with some mining rights on Io, it also forced them to accept Jovian extraterritorial rights in the Greenland ice cap: and many fear that the ancient and monstrous being which is the Overlord of Jupiter is still unsatisfied.
 Different from Hitler's notions, but almost as vainglorious. (All Nazi government buildings are unnecessarily large and look fitted more to a world-wide or even solar-system-wide empire rather than one which is objectively a not-too-large chunk of western Eurasia).
 This is a PulpVerse: since SF writers of the 30's didn't imagine Hitler would take as much trouble as he did OTL with the Jews, the Holocaust didn't happen (although 7 decades of energetic, um, "support for emigration" has left the Reich essentially Jew-free, even in its Polish territories.)